Description of Business - Additional Information (Detail) musical_composition in Millions	3 Months Ended
	Dec. 31, 2019 musical_composition country songwriter
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of countries in which Recorded Music activity conducted (more than) | country	70
Minimum number of musical compositions on which Company owns or controls rights (more than) | musical_composition	1.4
Number of songwriters and composers (over) | songwriter	80,000